They actually made a great deal of fun of these things at a recent defensive shotgun class.
I think the idea is that they don't perform anywhere near as well as federal flight control 8 pellet 00. They shot all kinds of loads in front of us, and when I got home...I ordered a couple cases of the federal flight control 8 pellet loads.
I was shooting the 9 pellet loads, and the difference was noticeable. The 8 pellet flight control shoots a tight group with no fliers.

hmmmmmm, the 7.5 shot would be all but worthless. but the #4 buck would be good.

Watch this vid. He did have a couple of failures with them going fast.

If I had a single or double barrel shotty for the wife I would use the #4 shells. But I think not in my pump and they certainly would not work in my auto loader as even full size bird shot does not cycle reliably. Only heavy loads. I bet the reduced recoil tactical buck we spoke about before probably kicks about the same as these shorty shells.

Having extra capacity is awesome but not at the expense of even 2% reliability. We are talking self defense not hunting.